A search for the appearance of tau neutrinos from numu a nu tau oscillations in the atmospheric neutrinos has been conducted using the atmospheric neutrino data from the Super-Kamiokande-I and the Super-Kamiokande-II experiment. A tau neutrino enriched event sample is selected by using the event topologies of the decay of tau leptons produced in charged-current weak interactions. An excess of tau neutrino signals is observed, and a best-fit tau neutrino appearance signal of 162 +/- 59 (stat.) +21-56 (sys.), which disfavors the no tau neutrino appearance hypothesis by 2.1 sigma. This is consistent with the expected number of tau neutrino events, 121 +/- 39 (sys.) for Deltam2 = 2.4 x 10-3eV2, assuming the full mixing in numu a nutau oscillations. The Super-Kamiokande atmospheric neutrino data are consistent with tau neutrino appearance from numu a nutau oscillations.A block diagram of the ATM board is shown in Figure 2.14. Each PMT ... Two
VME crates are installed in each electronics hut, and each VME is connected to 6
SMPs. The SMP ... This online host computer assembles the data into aeventsaanbsp;...